DESCRIPTION (Abstract of the application) Changes in gene expression are at the heart of many cellular responses to internal or external stimuli. In the case of disease, such changes may be causative or secondary in response to the disease process. Spotted cDNA microarrays are emerging as a powerful tool for large scale analysis of these gene expression patterns. With NIDDK support, The Jackson Laboratory (TJL) staff have used genetic approaches to study obesity, diabetes, gallstone disease, inflammatory bowel disease, and polycystic kidney disease and made major contributions to understanding the genes underlying or predisposing to these conditions. cDNA microarrays will provide further insights into the diseases they study, by enhancing QTL analysis and by the ability to monitor disease progression. To enable TJL NIDDK funded researchers and their colleagues within and outside the institution to use expression arrays in their research programs, we will establish a comprehensive gene expression array service that will be integrated into TJL's Shared Scientific Services. We will also make use of existing strengths at TJL in biostatistics and bioinformatics in developing this service. We will expand an existing gene expression service to encompass production, processing, and analysis of cDNA microarrays. We will also provide gene expression arrays designed for routine diagnostic use, and develop reference standards to allow comparison of expression array data across laboratories and over time. TJL has recognized strengths in bioinformatics and the statistical analysis of genetic and gene expression data. This will allow us to expertly and efficiently analyze array data and disseminate them to the scientific community. We will develop new statistical analysis methods and incorporate these into our service. Through lectures at TJL courses and workshops, our visiting investigator program and a postdoctoral training position in biostatistical analysis of array data, we will promote this new research field. One of the three missions of TJL is to provide resources to the scientific community. The laboratory has a long history of resource sharing and has established distribution channels and bioinformatics support. Experimental data, novel analysis methods, reference standards, and array materials will be made immediately public, and shared without undue restrictions. Processed data will be incorporated into the mouse Gene Expression Database (GXD).